There are innumerable things in the world, and each thing has endless varieties. If you try to experiencing everything first before deciding that there is no happiness in it, your whole life pass in this endeavor.
There are people who run after money all their lives, and yet do not decide that it does not have the happiness they are seeking. Again, if you finally do come to the conclusion that the world is not a place of happiness, but the mind doubts whether or not there is happiness in God, then what will you do?
As human beings, God has bestowed us with subtle intellects that can make this decision even without experience. Broadly, the intellects of living beings can be classified into four categories:
1. The lowest is the intellect of an insect. It is attracted to the fire. On coming near the flame, it gets burnt. But it does not learn from the experience, and commits the same mistake repeatedly.
2. The intellect of a cat is subtler. If it sits on a hot place, it learns from its experience. In future, it refuses even to sit on a cold plate, in apprehension that it may get burnt.
3. The intellect of sheep is even subtler. It has never been attacked by a wolf. But the moment it sees a wolf, it perceives impending danger and runs for its life.
4. The intellect of human is even subtler. Merely by intellectual discrimination, without seeing or experiencing, they are expected to reach the conclusion that there is no happiness in the world.
Actually, everyone has had experience of the world to a lesser or greater extent. We made the desires of the senses and strived hard to satisfy them. What was the experience each time? For a moment the desire is quenched, but then it arose again with redoubled intensity. This is the nature of all worldly desires, whether they are teeny-weeny cravings that you have made innumerable times in your lives or the bigger desires that loom more largely on your mind. The principle is exactly same. So we should utilize our experience to date, to reach a blanket conclusion about the nature of all worldly desires. That is what God expects us to do, and that is the instruction of the scriptures.